Commentary for Berakhot 44:2

LET US EXAMINE HOW EZRA INSTITUTED [THIS ORDINANCE]. There are many disagreements throughout the entire Gemara about Rabbinic enactments. The Gemara almost never suggests – let us see how the original ruling was instituted. Tosfos explains why the Gemara suggests that here. In many places in regard to other Rabbinic enactments the Gemara does not ask this question, but here it is different because it is something that regularly occurs every day, therefore we remember the nature of the original enactment.